Casey's blog

In reading my recipes you may notice that kale is used heavy-handedly in juices, salads, and cooked meals. It's kind of the new cool kid on the leafy greens block.

Some carefully observing friends may ask: Why kale?

Besides the fact that it's beautiful curly leaves and dark green hue make it an amazingly sexy cruciferous crusader, there are many solid reasons to include this champion of champions in your diet. Here are six of them:

1. Scrap the botoxSick of spending money on anti-wrinkle creams? Eat more kale. It's a superstar in the arena of carotenoids and flavonoids, two powerful antioxidants that protect our cells from free radicals that cause oxidative stress. With the addition of high doses of celebrity antioxidants vitamin C, vitamin A, and manganese, kale is a smart choice in the battle against cellular oxidation.

2. Still walking at 100..One cup of kale provides about 10% of the RDA of omega-3 fatty acids that helps regulate the body’s inflammatory process. A megadose of vitamin K further aids to fight against excessive inflammatory-related problems, such as arthritis, autoimmune disorders, and asthma. Kale's whopping dose of vitamin K (there's 1327% of the RDA in one cup) is necessary for the synthesis of osteocalcin, a protein that strengthens the composition of our bones.

3. ..and still seeing at 100!With over 192% of the RDA of vitamin A, one cup of kale keeps our eyesight sharp, is an effective antioxidant, boosts immunity, maintains healthy bones and teeth, prevents urinary stones, and is essential to our reproductive organs. Kale also has plenty of star anti-oxidant vitamin C, which lowers blood pressure, ensures a healthy immune system, and fights against age-related ocular diseases, such as cataracts and macular degeneration.

4. Anti-cancerKale can be likened to the superhero of vegetables, especially green leafy ones. Deep green kale contains the highest levels of antioxidants of all vegetables. Kale's high content of flavonoids and antioxidants work together to prevent and even combat cancer, in particular colon, breast, bladder, prostate, ovarian cancers, and gastric cancer.

5. Digestion One cup of kale contains nearly 20% of the RDA of dietary fibre, which promotes regular digestion, prevents constipation, lowers blood sugar and curbs overeating. Kale contains the glucosinolate isothiocyanate (ITC) that fights the formation of H. pylori (Helicobacter pylori), a bacterial growth in the stomach lining that can lead to gastric cancer.

6. Happy hearts, brillant bloodThe high fibre content of kale lowers our cholesterol by binding with bile acids that the liver produces from cholesterol for digesting fat. Because many of these bile acids are coupled with fibre, the liver is charged with producing more bile acid to digest fat, and therefore requires more cholesterol to so, ultimately lowering the amount of cholesterol within our bodies.

The vitamin K in kale also prevents calcium build-up in our tissue that can lead to atherosclerosis, cardiovascular disease and stroke.

Where to get itYou can buy kale (tuscan, dinosaur, red, cavolo nero or black) from many weekend markets - in Brisbane try the Northey St organic markets on a Sunday. Other than that, you can get it from health food stores such as Wray's and Mrs. Flannerys, but these may charge a premium.

Here on the Gold Coast many weekend markets sell kale, but personally we grow all our greens in our garden and have no shortage of kale - it's very easy to grow and loves sunlight.

Rotate your GreensKale is moving out of season now - Spring is the best time for growing and harvesting. Now that it's Summer we are replacing kale with other types of greens to match the seasons - in our juices we are using asian greens such as bok choy and choy sum.

I tend to rotate my intake of different greens with the seasons - it's cheaper, helps you to stay in sync with environmental change and attuned to your natural surroundings, reduces the risk of plant toxin overload (spinach overload can be dangerous!) and also to widen the range of micronutrients I get from the greens.

How to use itWash kale before use, and don't discard the outer, deep green leaves - these contain rich amounts of carotenes and indoles. Kale is good juiced, blended in green smoothies, chopped finely in raw salads, steamed or stir-fried. For non-vegans, its strong taste goes well with eggs, bacon and cheese. My favourite use for it is classic Green Juice, or in a mixed cooked / raw salad like this Roasted Earth Vegetable, Kale & Dill Salad. Kale, like spinach, shrinks a lot during cooking, so make sure you add plenty to the pan!

Great news about kale, as we've taken to eating loads of it. But three questions for you.

First, if you're using a slow press juicer, do you get any fibre? I thought the fibre was left behind.

Second, vitamin A is something on which you can O/D and it has some significant adverse effects. How much kale is too much if you're getting nearly twice your RDA in one juice? After all, loads of other foods have vitamin A added to them too, plus if you're popping a multi-vitamin, you may well end up with too much.

And finally, I can't help but wonder whether there are foods you shouldn't mix together in a juice. For example, do the good effects of one food actually nullify the good effects of another because they work in opposite ways? Not sure of any specific examples, but I know that there are foods you shouldn't eat together: anything with calcium and anything with iron are useless together as they bind to each other and you don't get the benefit of either mineral. How about with veggies, are there any poor combinations?

Keep up the great blog!

Chris

Reply

Casey Conroy

4/12/2011 07:20:09 am

Hi Chris, fantastic questions! Let's get to answering them.

1. Bingo, if you're JUICING the kale, then even though you'll be getting the vitamins and organic water straight into the bloodstream, you will get close to zero fibre out of it. Only if you eat it whole in salads, stir-fries etc will you get the roughage edge, so share your kale around your kitchen!

2. Vitamin A is definitely something you can overdose on, especially if you're a pregnant woman (which I know for a fact, Chris, you are not, phew!) Vitamin A comes in two main forms - pre-formed vitamin A and provitamin A.

Pre-formed vitamin A (retinol or retinal) is found in foods of animal origin such as cod liver oil, beef liver, some seafood, butter, whole milk and egg yolks. Hence all that fried liver your crazy Ukranian "aunty" used to force you to eat (or was that just me?)

Provitamin A is another word for the plant pigments we know as carotenes (or carotenoids), with beta carotene being the most famous of these.

The RDI for Vitamin A is measured in RE, or retinol equivalents. One unit of vitamin A you get from an animal source is equivalent to about 6 units of Vitamin A (carotenes) from a plant source. They are also biochemically different and behave very differently in the body.

Due to the variation in potency and biochemical structure of the two types of Vitamin A, it's pretty hard to overdose on beta-carotene.

The form of vitamin A that comes from kale is mainly carotene. So even though a cup provides 192% of the daily value of "vitamin A", since this is a plant source of vitamin A, it's very difficult if not impossible to overdose on it, overdose implying the arising of health risks.

Most doctors and nutritionists agree that eating food sources of vitamin A, particularly plant-based food sources, is safe and healthy. Although in my poorer uni-student days I did go through a serious carrot and pumpkin phase and ended up with yellow palms - no other side effects were ntoed!

It's only when people are taking serious doses of vitamin A supplements that things can get tricky.

Too much vitamin A can result in unwanted side effects, and in the case of pregnant women taking too much vitamin A can lead to severe birth defects in unborn children. Unless you have been diagnosed with a deficiency, I would recommended that you EAT foods high in vitamin A if you want to ingest more of this fat-soluble vitamin, rather than take a supplement. And go easy on aunt Marianna's fried liver.

3. Finally, about the mixing of plant foods and concerns over inhibited mineral absorption. You're absolutely right, some plants contain compounds that inhibit the absorption of minerals such as calcium and iron.

For example, the oxalic acid in spinach binds with iron, which inhibits iron absorption. However you can improve the absorption of iron from spinach by eating it with foods that enhance iron absorption, such as high vitamin C foods such as citrus, strawberries and capsicum.

In addition to consuming vitamin-C-rich fruits to enhance iron absorption from things like spinach, you can plan your meals to include meat, fish or poultry (if you're not vegetarian) along with spinach. These sources of heme-iron-rich food improve the absorption of non-heme iron from spinach.

For vegetarians, other vegetables such as broccoli, Brussels sprouts, tomatoes, tomato juice, potatoes and green and red peppers also improve absorption of iron from spinach.

Yet more discerning for spinach-lovers, is that the oxalate content in spinach also binds with calcium, decreasing its absorption too! As you mentioned, calcium and zinc in any food also limit iron absorption - these three stooges tend to all inhibit the absorption of the other!

Because of this, the calcium in spinach is the least bioavailable of calcium sources. By way of comparison, the body can absorb about half of the calcium present in broccoli, yet only around 5% of the calcium in spinach.

Mother nature can be complicated, but she's also clever and provides not just IRON in spinach or CALCIUM in kale, but a plethora of other phytochemicals and micronutrients that work together in a great symphony we barely understand.

You don't need a masters in nutritional biochemistry to eat well! Just eat a wide variety of foods, especially plant foods. The vitamin C in your capsicum will enhance the iron absorption from your spinach which may be encroached upon by the oxalic acid in your okra.

As long as you're not just eating spinach (which would get boring fast) and you're rotating you intake of green leafies among other fruit and vegies, you should be ok!